Latching mechanism for a modular gunstock

ABSTRACT

The present invention is a modular stock system for rifles. The system replaces the rifle&#39;s buffer tube with a modified one containing a mount for a constant cheek weld and a rail track for adjustment. A stock module then mounts on the replacement buffer tube. The stock module is interchangeable depending on the user&#39;s needs. Various configurations of the stock module are discussed, including adjustable stocks, fixed stocks, and specialized stocks. The stock module may be made even further modular by the addition of rail system. The latching mechanism is also capable for uses other than with rifle stocks where relative longitudinal motion of two pieces is required.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in part application based onearlier filed application Ser. No. 10/180,429, filed on Jun. 25, 2002,which is herein incorporated by reference.

FIELD OF INVENTION

[0002] The present invention relates to a latching mechanism for anadjustable rifle stock and more particularly to a cam-type latchingmechanism structured for a modular gunstock that provides a constantsurface for a uniform cheek weld and the option of a variable lengthfeature.

BACKGROUND OF THE INVENTION

[0003] Adjustable gunstocks are known in the prior art. For example,U.S. Pat. No. 4,735,007 to Gal (1988); U.S. Pat. No. 4,327,626 toMcQueen (1982); U.S. Pat. No. 3,442,042 to Gilbert (1967); U.S. Pat. No.3,348,328 to Roy (1966); U.S. Pat. No. 3,267,601 to Roy (1964); U.S.Pat. No. 3,137,958 to Lewis, et al. (1962); U.S. Pat. No. 5,827,992 toHarris, et al. (1998) and U.S. Pat. No. 2,900,877 to McClenahan (1956)are all illustrative of the prior art.

[0004] The current standard in automatic and semi-automatic rifles is tohave a stock capable of receiving and covering a recoil absorptionappendage, or “buffer tube”, shown in the '992 and '877 patents. Themost popular of the available adjustable stocks follow in form to the'328 patent, which is to say they use a spring loaded latch to bias apin inside a provided adjustment hole. When a user wishes to adjust thestock, a simple compression of the spring/latch assembly is all that isrequired to release the pin and, therefore, adjust the stock. The '626patent operates with a tooth-and-groove assembly which, otherwise,follows the same principles. In both cases, compression of the spring isnecessary for adjustment in both directions along any length beyond theproximate hole/groove. All of the adjustable stocks may have their buttportion removed, though they are not designed to have such a featurerepeatedly used, much less have additional stock modules to exchange. Inthose cases where the stock moves longitudinally along the weapon, withno other motion relative to the weapon, the user must make somesacrifice as to one, if not both, of two features. The user either losesconstant and uniform cheek weld to the weapon or stock stability. Thelack of uniform cheek weld can interfere with comfortable and preciseuse of the weapon. Stock stability can also interfere with preciseweapon use. The main cause of this sacrifice is the lack of a firm andreliable latching mechanism

[0005] While the aforementioned inventions accomplish their individualobjectives, they do not describe a truly modular stock, namely a stockwhere the butt portion is designed to be changed at the whim or need ofthe user. The present invention is a cam/tension lock that enables theuser to have not only a controlled extension, but also an unrestrictedand silent compression and extension of a truly modular stock, asdescribed in the parent application. None of the disclosed stocks havean adjustable preset lock to use in conjunction with an unrestrictedadjustment. Finally, none of the disclosed stocks present a surface fora constant cheek weld while simultaneously having a sturdy, longitudinaladjustment capable stock, much less a uniform cheek weld with differentstock types, still much less a latching system designed for such amodular stock system. In this respect, the latching system according tothe present invention departs substantially from the usual designs inthe prior art. In doing so, this invention provides more stable andstrong latching mechanism for modular gunstock that allows for a uniformand identical cheek weld for different stock modules, even whilesimultaneously adjusting the stock length of an adjustable stock.

SUMMARY OF THE INVENTION

[0006] In view of the foregoing disadvantages inherent in the knowntypes of gunstocks and their associated latching mechanisms, thisinvention provides an improved latching mechanism. As such, the presentinvention's general purpose is to provide a new and improved latchingmechanism for a gunstock having multiple functionality, dependent uponchosen stock modules. The invention will provide simultaneous adjustmentof the stock while providing a constant, uniform cheek weld on the stockwhen used with an adjustable stock module. The invention will alsoprovide an identical cheek weld surface with a sturdy stock if a fixedstock is used.

[0007] To provide the improved features, the gunstock, as described andclaimed in the parent application, comprises both a fore and buttportion. The fore portion consists of a buffer tube attachable to theweapon's receiver and a cheek plate extension essentially parallel tothe buffer tube. Located on the underside of the buffer tube is a railtrack. The rear portion consists of a receiving cylinder of sufficientlength and width to receive the buffer tube of the fore portion. Locatedon the lower rim of the cylinder is the compression latching mechanism,designed to interface with the rail track. Rearward of the receivingcylinder is the stock butt and any other accessories as required by theuser. In the preferred embodiment, the cheek plate is fused to thebuffer tube, presenting a wider rest for a user's cheek, and the rearportion comprises a receiving cradle, or semi-cylinder, which interfacesalong a pair of attachment grooves located on either side of the buffertube, having a distal relation with the cheek plate. Interface detentsare provided along lateral sides of the buffer tube for the purpose ofinterfacing with the latching mechanism

[0008] The latching mechanism according to this invention essentiallycomprises a cam type interface system. The mechanism is located withinthe rear portion of the gunstock and is situated to interface with thebuffer tube in the fore portion, specifically the rail track. In thepreferred embodiment, the latching mechanism has a cam anchor situatedso as to interface with the rail track and a bicuspid tooth, situated sothat the cusps of the tooth are on either side of the cam anchor and soas to interface with the detents on the buffer tube in pairs. In sodoing, the latching mechanism provides not one, as is the standard inthe art, but three points of contact with the buffer tube, resulting ina firmer and more secure hold.

[0009] The more important features of the invention have thus beenoutlined in order that the more detailed description that follows may bebetter understood and in order that the present contribution to the artmay better be appreciated. Additional features of the invention will bedescribed hereinafter and will form the subject matter of the claimsthat follow.

[0010] Many objects of this invention will appear from the followingdescription and appended claims, reference being made to theaccompanying drawings forming a part of this specification wherein likereference characters designate corresponding parts in the several views.

[0011] Before explaining at least one embodiment of the invention indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangements of thecomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments and of beingpracticed and carried out in various ways. Also it is to be understoodthat the phraseology and terminology employed herein are for the purposeof description and should not be regarded as limiting.

[0012] As such, those skilled in the art will appreciate that theconception, upon which this disclosure is based, may readily be utilizedas a basis for the designing of other structures, methods and systemsfor carrying out the several purposes of the present invention. It isimportant, therefore, that the claims be regarded as including suchequivalent constructions insofar as they do not depart from the spiritand scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a side elevation of the latching mechanism according tothe present invention.

[0014]FIGS. 2a-f display a blown-apart view of the latching mechanism.

[0015]FIG. 2a is a side elevation of one half of a latch, detailing thelatch's interior.

[0016]FIG. 2b is a side elevation of the latching mechanism's actuatorand cam anchor, from FIG. 2a

[0017]FIG. 2c is a side elevation of the latching mechanism's tooth andcam mechanism, from FIG. 2a.

[0018]FIG. 2d is a front elevation of the one half of a latch of FIG.2a.

[0019]FIG. 2e is a front elevation of the latching mechanism's actuatorand cam anchor.

[0020]FIG. 2f is a front elevation of the latching mechanism's tooth andcam mechanism.

[0021]FIGS. 3a-c are progressive side elevations showing the use of thelatching mechanism with an adjustable stock.

[0022]FIG. 4 is a side elevation of an adjustable stock module.

[0023]FIG. 5 is a cross-section of the module of FIG. 4, taken alongline 5.

[0024]FIG. 6 is a bottom plan view of the modified buffer tube module.

[0025]FIG. 7 is a side elevation of the modified buffer tube module.

[0026]FIG. 8 is a cross section of the buffer tube module of FIG. 7taken at line 8.

[0027]FIGS. 9a-c are partial cross sections of the latching mechanismand stock of FIGS. 3a-c respectively.

[0028]FIG. 10 is a bottom plan view of the buffer tube module andassociated preset system.

[0029]FIG. 11 is a cross-section of the buffer tube module of FIG. 11,with the preset clip removed, taken along line 11.

[0030]FIG. 12 is two close-up views of the preset tooth.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0031] With reference now to the drawings, the preferred embodiment ofthe modular gunstock will be explained.

[0032] With reference to FIGS. 1, 2a-f the latching mechanism 20incorporates a latch body 22, divided in two halves, a bicuspid latchtooth 28 and an associated cam mechanism 26. A safety latch 24 attachedto a spring mount 25 with a safety tooth 27 may be incorporated, asshown in FIG. 1. Latch 20 is axially mounted about two mounting holes34, one half of latch body 22 in each hole 34, in a manner to interfacewith rail track 8 and tooth interfaces 5, shown in FIGS. 3 and 4.

[0033] Latch 20 has three settings, shown in FIGS. 3 and 9, whichactivate cam mechanism 26 to bias tooth 28 against tooth interface 5.Latch body 22 a is pulled backwards to disengage latch tooth 28 fromtooth interfaces 5. This setting allows free adjustment, forwards andbackwards, of the module. In the second setting, cam mechanism 26operates to bias latch tooth 28 into a middle, ratcheting position. Thelatch tooth has a forwards-facing angle 30, which allows latch tooth 28to catch the rail track if the stock module is pushed forwards, butdisengages from tooth interfaces 5 for backwards extension. The finalposition is a locked position which forces latch tooth 28 into an almostvertical position. Cam anchor 32 is also forced into rail track groove6. Safety latch 24 is forced to interface with the stock module with itssafety tooth 27 by spring mount 25. The interface prevents latch body 22from being compressed accidentally. Spring mount 25 is embedded intolatch body 22 in such a manner that when safety latch 24 is mounted uponit, safety latch 24 is flush with latch body 22. As tooth 28 is furtherbiased against interface 5, stock module 12 is locked into relativeposition against the buffer tube module 2. This construction allows athree point locking system that gives more security and stability thanthe prior art single point locking systems. As such, the latchingmechanism may be utilized in fixed stock modules. In FIGS. 3 and 9, 22 adepicts a locked setting; 22 b depicts an extension only setting; and 22c depicts a free motion setting. In all embodiments, rails 18 are slidthrough tracks 9 for proper guidance and hold.

[0034] The gunstock is composed of a modified buffer tube module 2 and astock module 12. Buffer tube 2 fits on rifle 1 by replacing the existingbuffer tube of the rifle with the buffer tube module 2. In addition,referencing FIGS. 3 and 4, rail track 8, with individual lateral grooves6 and single transverse groove 7, is disposed towards the ground andcheek mount 10 is disposed upwards and is generally parallel to buffertube 4. Two longitudinal tracks 9 are disposed slightly underneath cheekplate 10 providing attachment tracks for stock module 12. Ideally, thecheek plate 10 is fused onto the buffer tube 2. However, in alternativeembodiments, enough space can be left between buffer tube 4 and cheekplate 10 to allow for unhindered motion of a cylindrical stock module.Tooth interfaces 5 are disposed underneath the longitudinal tracks 9.

[0035] Referring to FIGS. 6 and 7, stock module 12 has a receivingcradle 14 that fits over buffer tube module 2. Two attachment rails 18are disposed at the upper two edges of the cradle 14. Behind receivingcradle 14 is the butt 16 of the stock. Butt 16 may be modified invarious configurations, depending on the needs of the user. In theadjustable embodiment shown in FIG. 1a, latching mechanism 20 interfaceswith rail track 8 via a bicusped tooth 28 and cam anchor 32.

[0036] In an alternate embodiment, shown in FIGS. 10, 11, and 12, acatch tooth 50 is disposed above the latching mechanism to interfacewith transverse channel 57. Catch tooth 50 is mounted upon catch base52, forming a shape reminiscent of a capital “T”, and is biased byspring 54 into a central position. Stop bar 56 is a clip insertable intothe lateral grooves 55 of transverse channel 57. Stop bar 56 has agroove 59 corresponding with transverse channel 57 except that groove 59is almost dissected by projection 58, leaving enough room for tooth 50to pass through if biased to one side. In so doing, a preset function isadded to this embodiment. A user simply inserts a stop bar at a desiredlength. When extending the stock module, tooth 50 will be blocked byprojection 58, thus arresting extension of the stock module. To pass thestop bar, the user presses stop base 52 to one side, allowing tooth 50to pass. A spring or other biasing means then returns tooth 50 to acentral position when pressure is released. A second stop bar, ideallywith projection 56 facing a different direction, may be added forfurther security. In addition, the back of the transverse groove 57 maybe fashioned with such a projection to prevent the stock module fromaccidentally being pulled off the buffer tube module.

[0037] Although the present invention has been described with referenceto preferred embodiments, numerous modifications and variations can bemade and still the result will come within the scope of the invention.Included in these variations would be the use of this latching system instructures besides rifle stocks, as the present invention may be used inany situation wherein relative longitudinal motion, such as described inthe preferred embodiment, of two pieces is required. No limitation withrespect to the specific embodiments disclosed herein is intended orshould be inferred.

I claim:
 1. A latching mechanism and associated structure for a latchingsystem, said system having a structure module and a latch housingmodule, the system comprising: a. A bicuspid tooth mounted upon a cammechanism; b. A cam anchor, likewise mounted on the cam mechanism saidanchor situated between the cusps of the bicuspid tooth; c. An actuatorfor the cam mechanism to bias the tooth and cam anchor; and d.Associated structure on the structure module capable of receiving thebicuspid tooth and cam anchor; wherein the latching mechanism issituated within the housing module and the actuator biases the tooth andthe anchor into the structure provided on the structure module.
 2. Thelatching mechanism of claim 1, wherein the bicuspid tooth interfaces thestructure module on opposite lateral sides and the cam anchor interfacesthe structure module on a bottom side.
 3. The latching mechanism ofclaim 2, wherein the cam mechanism positions the bicuspid tooth and camanchor into three positions relative to the housing module, the bicuspidtooth being angled and the mechanism primarily displacing the tooth inan angular manner so that the first position allows for free motion ofthe housing module relative to the structure module, the secondposition, in which the bicuspid tooth is only marginally in contact withthe structure module and the cam anchor is not in any such contact,allows for unidirectional motion of the housing module and the thirdallows for no motion, both tooth and anchor being in secure contact withthe structure module.
 4. The latching mechanism of claim 3, furthercomprising a safety latch located upon the actuator and interfacing withthe housing module when in a locked position so as to prevent accidentalactuation.
 5. The latching mechanism of claim 4 further comprising alaterally biasable interface tooth positioned to interface with thebottom side of the structure module.
 6. A latching mechanism andassociated structure for an adjustable stock, said stock having amounting module and a stock module, the mechanism comprising: a. A railtrack, located on an underside of the mounting module; b. A plurality ofinterface detents, located in pairs on opposite lateral sides of themounting module; c. A cam actuated latch, located within the stockmodule in a manner to interface with the mounting module when themounting module is inserted into to the stock module, the latch furthercomprising: i. An actuator; ii.a cam mechanism actuator, iii.a camanchor, in communication with the can mechanism and positioned tointerface with the rail track iv.a bicuspid tooth in communication withthe cam mechanism, the cusps positioned on opposite sides of the camanchor and positioned to interface with one of a pair of the detentslocated on either lateral side of the mounting module; wherein, theactuator positions the cam mechanism relative the mounting module. 7.The latching mechanism and structure of claim 6, the cam mechanismfurther comprising a three-staged mechanism, positioning the cammechanism, and associated tooth and anchor, into open, single-directionopen, and closed positions, the single-direction open position allowingno interface of the anchor with the mounting module and partialinterface of the tooth with the detents in a manner to allow the stockmodule to be adjusted in a unidirectional manner relative to themounting module.
 8. The latching mechanism and structure of claim 8,wherein the tooth is actuated by the cam mechanism in an angular manner,and the detents are angled in a manner to facilitate unidirectionalmovement when the cam mechanism and tooth are positioned in thesingle-direction position.
 9. The latching mechanism of claim 8, furthercomprising a safety latch located upon the actuator and interfacing withthe stock module when in a locked position so as to prevent accidentalactuation.
 10. The latching mechanism and structure of claim 6, furthercomprising a rail interface tooth and the rail further comprises achannel dividing the rail in a longitudinal manner, the tooth beingbiased in a detent position between individual rails of the rail trackso as to block relative motion of the stock module but also beingbiasable to interface with the channel so that relative motion of thestock is possible.
 11. The latching mechanism and structure of claim 10,the cam mechanism further comprising a three-staged mechanism,positioning the cam mechanism, and associated tooth and anchor, intoopen, single-direction open, and closed positions, the single-directionopen position allowing partial interface of the tooth with the detentsin a manner to allow the stock module to be adjusted in a unidirectionalmanner relative to the mounting module.
 12. The latching mechanism andstructure of claim 11, wherein the tooth is actuated by the cammechanism in an angular manner, and the detents are angled in a mannerto facilitate unidirectional movement when the cam mechanism and toothare positioned in the single-direction position.
 13. The latchingmechanism of claim 12, further comprising a safety latch located uponthe actuator and interfacing with the stock module when in a lockedposition so as to prevent accidental actuation.
 14. The latchingmechanism of claim 10, further comprising at least one clip, insertablewithin the rails of the rail track, thereby at least partially blockingthe channel along the rail track and arresting motion of the stockmodule relative to the mounting module.
 15. The latching mechanism andstructure of claim 14, the cam mechanism further comprising athree-staged mechanism, positioning the cam mechanism, and associatedbicuspid tooth and anchor, into open, single-direction open, and closedpositions, the single-direction open position allowing partial interfaceof the tooth with the detents in a manner to allow the stock module tobe adjusted in a unidirectional manner relative to the mounting module.16. The latching mechanism and structure of claim 15, wherein thebicuspid tooth is actuated by the cam mechanism in an angular manner,and the detents are angled in a manner to facilitate unidirectionalmovement when the cam mechanism and bicuspid tooth are positioned in thesingle-direction position.
 17. The latching mechanism of claim 16,further comprising a safety latch located upon the actuator andinterfacing with the stock module when in a locked position so as toprevent accidental actuation.